Oil well heater



June 27, 1933. F. M. LEWIS I I OIL WELL HEATER Filed May 25, 1932 Patented June 27, 1933 4 i UNITED STATES PATENT OFFICE FRANKLIN M. LEWIS, OF PORTLAND, OREGON" on. WELL HEATER Application filed May 25, 1932. Serial No. 613,516.

My invention is an electric heater for use onto the lower end of a perforated four-inch in oil wells to melt the parafline in the bottom iron pipe section 3 of about there feet in of the wells which restricts the flow of the oil. length. The upper end of the pipe section l am aware that electric oil well heaters have 3 is screwed into a four-inch iron pipe couheretofore. been devised but all such which pliug 4. g This coupling 4 has screwed into have come to my attention have been deficient it a disk 35 which is permanently secured in one way or another; some are objectionable about midway the ends of the coupling by because the life of the electrical units and welding as at 36. The disk 35 has a central power cables is too short; some make no adethreaded aperture into which is tightly quate provision to protect the electrical wires, threaded the plug of a heating unit of terminals. and contacts against short circuits -which more will be said later. due to water and moisture leaking into the The coupling lhas a four-inch pipe section heater or being deposited by condensation; 5of about twelve. inches in length screwed into some make no adequate provision to prevent it and this pipe section is in turn coupled, as

17 the insulation of the cables rotting due to the at 6, to the lower one of two iron pipe secpresence of oil seepage; others are too expentions 7, there being a partition disk 32 threadsive: others are. inefficient in operation, etc. cd into the coupling 6 and welded thereto as My invention has for its object to provide at 33. The disk 32 has three tapped holes (I an oil heater which is free from the objections for the spark-plug-type seal joints 18. above noted and one which will readily and The two pipe sections 7 are coupled tocil'ectivcly serve its intended purpose. gether by a coupling 8 which also carries a Other objects will in part be obvious and partition disk that is threaded into the in part be pointed out hereinafter. coupling and welded thereto as at 31. The

To the attainment of the aforesaid objects disk 30 has a central threaded hole into which i z and ends. the invention still further resides is screwed a one and one-quarter inch iron in the novel details of construction, combinapipe 27 about twelve inches long. The upper tion and arrangement of parts, all of which pipe section 7 is coupled to a two-inch iron will he first fully described in the following pipe 10 of any desired length by means of a r detailed description, then be particularly reducing joint coupling 9. The upper end of pointed out in the appended claims, reference the pipe 10 receives the stuffing box ring 11 being bad to the act ompanying drawing, in and the stufling box cable 12 which is screwed which thereon.

Figure 1a-1?) is a vertical longitudinal The cabletthrce-strand) 13 passes through H section of my improved heater. the stuffing box 12 and pipe 10, stufiing box Figure 2 is a horizontal section on the line 14 and pipe 27 into the lower pipe section 7. o 2 2 of Figure 1?). Suitable packing 37 is used in the stuffing Figure I) is a diagrammatic view hereinboxes to effect a water-tight joint where the after referred to. cable passes through. The cable 13 is a special In the drawing l have shown the preferred cable with varnished cambric insulation, with embodiment of my invention which I shall a cotton braid impregnated with a tar comnow describe in detail as the same has been pound over each conductor and surrounded made up for actual use, although I desire it by a suitable braid which will withstand understood that I do not wish to limit myself both heat and oil, and to some degree, water.

, to the siZes and proportions of parts herein- The pipe 27 has its upper end provided after specified except insofar as they may be with a stuffing box 15 and a stufiing box cable specifically recited in the appended claims. 14 through which the cable 13 passes and is in the embodiment of my invention .hown secured water-tight by suitable packing 37. 1 represents a four-inch iron pipe plug The several strands of the cable 13 are screwed into the lower end of a four-inch tipped with brass terminals 16 which are iron pipe coupling 2 that in turn is screwed threaded onto the projecting upper ends of the conductor rods 26. The rods 26 are secured in suitable insulators 17 held in sparkplug-type joints 18 that are threaded into the disk 32 1n a fluid-tight manner. The rods 26 are secured to the insulator by nuts 38-38.

Extra flexible asbestos covered copper wire connecting cables of suitable size have brass terminals 24 threaded to two of the rods 26 and to the two thread-rod terminals 25a of the heating unit 25. 20 are other flexible asbestos covered cables of suitable carrying capacity which have threaded terminals 24 for connecting the third thread-rod 26 with the thermostat 21. The thermostat is connected to the return terminal of the heater unit by a cable section 20 for a purpose presentl explained.

The t ermostat includes a housing 22 secured within the pipe 5 as at 23.

28 is a bale formed of steel bar welded at its ends to the upper extremity of the pipe 10. By means of this bale the heater may e secured to the lowering and raising tackle (not shown).

The plu 18 may have gaskets 34 11ke those of the or mary spark plugs in order to effeet a fluid and gas-ti ht seal.

In the heater whic I have built and successfully tested I have found that the presence of the pipe 27 and stufling box 1L15, etc. prevents water entering the p1p e 7 below the partition 30, thereb preventing short circuits in the chamber 0 the lower pipe section 7 and materially increasing the life and efficiency of the a paratus, the plu 25 bein screwed as and fl iud-tight in the dlsk 35 an the mem rs 18 bein snnilarly screwed into the disk 32, the chamber of the pipe 5 is maintained gas-tight.

Any water of condensation in the plpe 10 and the upper section of the pipe 7 next below it is tra ped in the chamber surroundin the pipe 2 %he arts 6, 32, 17 and 18 comprise a un1t assembly having several important features, namely it provides a convenient and easy means to connect and disconnect the lead-in cable 13 with the thermostat and with the heating element, both in assembling and dismantling the heater; it rovides additional insurance against water rom leakage or condensation (elements 17 extend above element 18 so as to provide in pipe 7 a second well for the collection of condensation); it makes a gas-tight chamber for the thermostat where an explosive mixture could form from the spark when the thermostat operates, and it provides a rigid connectlon for the conductors.

The thermostat which I use is of standard make and serves to operate arelay 39 to break the ignition circuit of the gas engine 40 which drives the dynamo 41 that furnishes power for the heating circuit 43 (see Figure 3) and thus prevents overheating the 011.

tion must withstand heat, oil, mechanical abrasion, and to some degree water or moisture; the thermostat must cut off the heater at a temperature which will not damage the heater or the oil; the thermostat chamber must be gas-tight to prevent a possible explosion due to spark of the thermostat; sim-' plicity of construction and selection of parts which can be obtained easily and fabricated in a small machine shop; ease of assembly and repair; the prevention of condensation and water from causin short circuits; and the housing must be 011 and gas-tight.

Recent tests under actual working conditions in the field have proved that my heater meets all of the above requirements.

From the foregoing description, taken in connection with the accompanying drawing, it is thought the complete construction, operation and advantages of my invention will be clear to those skilled in the art to which it relates.

What I claim is:

1. Inv an oil well heater, a tube composed of a series of pipe sections, couplings joining said sections end to end, artitions secured in said coupling between t e ends of the pipe sections to divide the tube into a plurality of separate chambers the lower one of which constitutes the heating chamber, the next above constitutes the control chamber and the second above constitutes the cable terminal chamber, a heater unit secured in the partition between the heating and control chambers with its heating element proper located in the heating chamber and its terminal elements located in the control chamber, a set of spark-plug-type rigid conductor units mounted in the partition between the control chamber and the cable terminal chamher, a thermostat in the control chamber, connector cables between said rigid conductor units and the thermostat and the heater unit terminals, a cable having a set of separate conductors enclosed in a common envelope passed downward into said tube and having its lower conductor ends located in said cable terminal chamber and provided with connectors coupling said ends to said rigid conof a series of pipe sections, couplings joinin said sections end to end, partltions secur in said couplings between the ends of the pipe sections to divide the tube into a plurality of separate chambers, the lower one of which constitutes the heating chamber, the next above constitutes the control chamber and the second above constitutes the cable terminal chamber, a heater unit secured in the partition between the heating and control chambers with its heating element proper located in the heating chamber and its termip nal elements located in the control chamber, a set of spark-plug-type rigid conductor units mounted in the partition between the control chamber and the cable terminal chamber, a thermostat in the control chamber, connector cables between said rigid conductor units and the thermostat and the heater unit terminals, a cable having a set of separate conductors enclosed in a common enve ope passed downward into said tube and having its lower conductor ends located in said cable terminal chamber and providedwith connectors coupling said ends to said rigid conductor units, there being a partition in the tube at the top of said cable terminal chamber which has an aperture for the passage of said cable, a standplpe secured at its lower end in said aperture, through which pipe the cable passes, and a stufling box at the top of said standpipe for sealing the cable thereto.

3. In an oil well heater, a tube composed of a series of pipe sections, couplings joining said sections end to end, partitions secured in said couplings between the ends of the pipe sections to divide the tube into a plurality of separate chambers, the lower one of which constitutes the heating chamber, the next above constitutes the control chamber and the second above constitutes the cable terminal chamber, a heater unit secured in the partition between the heating and control chambers with its heating element proper located in the heating chamber and its terminal elements located in the control chamher, a set of spark-plug-type rigid conductor units mounted in the partition between the control chamber and the cable terminal chamber, a thermostat in the control chamber, connector cables between said ri'gid conductor units and the thermostat and the heater unit terminals, a cable having a set of separate conductors enclosed in a common envelope passed downward into said tube and having its lower conductor ends located in said cable terminal chamber and provided with connectors coupling said ends to said rigid conductor units, there being a partition in the tube at the top of said cable terminal chamher which has an a erture for the passage of said cable, a stan pipe secured at its lower end in said aperture, through which pipe the cable passes, a stuifing box at the top of said standpipe for sealing the cable thereto, and

another stufling box at the upper end of said tube for sealing the cable thereto where it enters the tube.

4. In an oil well heater, a tube composed of a series of pipe sections and couplings for connecting them together end to end, transverse partitions threaded into and secured to said couplings to divide the tube into a series of four compartments, the lower one of which constitutes the oil heating compartment, the next above that constitutes the control comartment and the next above that constitutes the cable terminal comparment, while the uppermost compartment constitutes the cable entrance and sealing compartment, means by which lowering and raising tackle may be secured to said tube, the lowermost partltion havin a threaded hole, a heating unit including a eater proper and a mounting and terminal carrying plug, carried by said lowermost partition with the heater proper located in the heating chamber and the terminals located in the control chamber, the wall of the heating chamber being perforated, a thermostat in the control chamber, the second partition from the bottom having a plurality of threaded apertures, a set of spark-plug-type insulated conductor rod units screwed into the plurality of said threaded apertures, and having the ends of said rods located respectively in the control chamber and in the cable terminal chamber, a cable passed down into said tube and having its strands separately exposed in said cable terminal chamber and provided with connections secured to the adjacent ends of the respective conductor rods, means to seal the cable where it passes into the tube, and also adjacent the upper partition of the cable terminal chamber against passage of water and oil, a set of connector wire cables in said control chamber for effecting connections between said conductor rods and said thermostat and said heating unit terminals.

5. In an oil well heater, a tube composed of a series of pipe sections and couplings for connecting them together end to end, transverse partitions threaded into and secured to said couplings to divide the tube into a series of four compartments, the lower one of which constitutes the oil heating comthe wall of the heating chamber being per- 1 forated, a thermostat in the control chamber, the second partition from the bottomhavm a plurality of threaded a ertures, a set spark-plug-type insulate conductor rod units screwed into the pluralit of said threaded apertures, and having t e ends of said rods located respectively 1n the control chamber and in the cable terminal chamber,

a cable passed down into said tube and having its strands separately exposed 1n said cable terminal chamber and provided with connections secured to the adjacent ends of the respectivedconductor rods, means to seal the cable where it passes into the tube, and also adjacent the upper partition of the cable terminal chamber against passage of water and oil, a set of connector wire cables in said control chamber for effecting connections between said conductor rods and said thermostat and said heating unit terminals, said sealing means comprising a stufiing box at the upper end of said tube, a standpipe within the tube surrounding the cable and mounted fluid-tight on the upper partition of the cable terminal chamber, and a stufling box on the upper end of said standpipe to seal the cable therein.

6. In an oil well heater, a tube composed of a series of pipe sections and couplings for connecting them together end to end, transverse partitions threaded into and secured to said couplings to divide the tube into a series of four compartments, the lower one of which constitutes the oil heating compartment, the next above that constitutes the control compartment and the next above that constitutes the cable terminal compartment, while the uppermost compartment constitutes the cable entrance and sealing compartment, means by which lowering and raising tackle may be secured to said tube, the lowermost partition having a threaded hole, a heating unit including a heater proper and a mounting and terminal carrying plug, carried by said lowermost partition with the heater roper located in the heating chamber and t e terminal located in the control chamber, the wall of the heating chamber being perforated, a thermostat in the control chamber, the second partition from the bottom having a plurality of threaded apertures, a set of spark-plug-type insulated conductor rod units screwed into the plurality of said threaded apertures and having the ends of said rods located respectively in the control chamber and in the cable terminal chamber, a cable passed down into said tube and having its strands separately exposed in said cable terminal chamber and provided with connections secured to the ad acent ends of the respective conductor rods, means to seal the cable where it passes into the tube, and also adjacent the upper partition of the cable terminal chamber against passa e of water and oil, a set of connector wire'ca les 1n said control chamber for efiecting connections between said conductor rods and said thermostat and said heating unit terminals, said spark-plug-type insulated rod units each including insulators which are elongated to extend a substantial distance above the partition which carries them for the purposes specified.

7. In an oil well heater, a tube com sed of a series of pipe sections and couplings for connecting them together end to end, transverse partitions threaded into and secured to said couplings to divide the tube into a series of four compartments, the lower one of which constitutes the oil heating compartment, the next above that constitutes the control compartment and the next above that constitutes the cable terminal compartment, while the uppermost compartment constitutes the cable entrance and sealing compart-' ment, means by which lowering and raising tackle may be secured to said tube, the lowermost partition having a threaded hole, a

heating unit including a heater'proper and' a mounting and terminal carrying plug, carried by said lowermost partition with the heater proper located in the heating chamber and the terminal located in the control chamher, the wall of the heating chamber being rforated, a thermostat in the control chamer, the second partition from the bottom having a plurality of threaded apertures, a set of spark-plug-type insulated conductor rod units screwed into the plurality of said threaded apertures, and having the ends of said rods located respectively in the control chamber and in the cable terminal chamber, a cable passed down into said tube and having its strands separately exposed in said cable terminal chamber and provided with connections secured to the adjaceiit ends of the respective conductor rods, means to seal the cable where it passes into the tube, and also adjacent the upper partition of the cable terminal chamber against passa e of water and oil, a set of connector wire ea les in said control chamber for effecting connections between said conductor rods and said thermostat and said heatin unit terminals, said sealing means comprising a stutfing box at the upper end of said tube, a standpipe within the tube surrounding the cable and mounted fluid-tight on the upper partition of the cable terminal chamber, and a stuliing box on the upper end of said standpipe to seal the cable therein, said spark-plug-type insulated rod units each including insulators which are elongated to extend a substantial distance above the partition which carries them for the purposes specified.

FRANKLIN M. LEWIS. 

